Feed restriction during late lactation in the

III.

^-

SOWS

AND PIGLETS FEEDING

Feed restriction during ^{late lactation in the}

^sow

P. H.

DUÉE,

M.

ÉTIENNE J.

^LEBOST

Station de Recherches sur

l’Elevage

^{des Porcs, J. N.}

R. A.,

^{C. N. R.} Z., 78350

Jouy

^en

,Josas

This

experiment

^{was made on}

3 6 Lavge

^{White sows after 1St or 2nd}

farrowing ( 75

and zg p. ^fOO

respectively)

with the aim of

determining

^the effects of a severe feed restriction

( 50

p.

roo) during

the last two weeks of a lactation

period

^{of 35}

days.

At the moment when the sows were divided into groups

(gz

groups of IS ^sows

each) they

exhibited

comparable performances

^with

respect

^to

weight (gestation

^net

weight + lactation weight variation,

i.e. !- 33

kg,

^{on an}

average)

and number of suckled

piglets (8. 1

^{on an}

average).

The diet

containing

IS.5 p. ¹⁰⁰crude

protein

and 295o kcal

digestible

energy per

kg

^{was offered}

to the animals either at a level close to ad libitum

feeding ( 5 kg/day)

^or restricted

( 2 . 5 kg/day).

Reduction of the

feeding

^level

significantly

increased the

weight

loss of the sows

during

^the

last two weeks of lactation

( 20 . 2

^versus m.3

kg)

^and

mainly during

the first week of the

experi-

ment. Parallel to that the

growth

^{of the}

piglets

decreased : 16 p. ^ioo decrease of the litter

weight

from 21 to 35

days

in the restricted group and this decrease ^was also more marked

during

^the

first week of the

experiment ( 23

p.

too).

The effects of this feed restriction did not seem to have any

repercussion

^{on the}

performances

of the sows

during

^the

subsequent reproductive cycle (weight

variation of the _{sows ;} number of

piglets

^at

farrowing). ^However,

^{it was} observed that the number or animals

returning

^{in ocstrus}

after the

mating following weaning

^was

larger.

Effect of fasting multiparous

^sows

^the day

of weaning

^on

^their reproductive performances

J. LEBOST, M. BONNEAU, J.

RETTAGLIATI A. AUMAITRE Station de Recherches sur

l’Élevage

^des

Porcs,

^{I. N. R.}

A.,

^{C. N. R.} Z.,

78350

Jouy

^en

Josas

Fourty Large

^White sows were distributed

into

1 groups

taking

into account the mean

weight

^and

parity

of the animals in order to

study

the eventual influence of feed and water star- vation on the

day

^of

weaning,

^{after a lactation}

period

of 35

days.

^The treatments involved sup-

pression

^{of water}

only (group i), suppression

^{of feed}

only (group 2 ), suppression

^{of water and}

feed

(group 3 ), suppression

of feed and administration of 50 g sodium

sulphate

per animal. The

weaning-oestrus

interval varied little from one group ^to another

(group

^{i :}

7 .6 days,

^{group 2 :}

7.6 days,

group 3 : 9.3

days,

group 4 : m.9

days).

^The

weaning-conception

^interval

( 12 . 7 - 7 .6- 1 6. 0

and 21.8

days)

^{did not}

significantly

differ because of a

large

intra-treatment

variability ( 73

^to

130

p.

100 ). However,

^{it was} in the group where feed ^was

suppressed

^{and not water on the}

day

^of

weaning

^{that no return to heat was noted versus 20to} 30 p. ¹⁰⁰in the other groups.

But,

^neither

weight gain performances during subsequent gestation

^nor

prolificacy

of the animals at next

farrowing

^{were affected}

by

either of these treatments.

Influence of the feeding ^{level between} weaning

and mating

^on

^the reproductive performances ^of multiparous

^sows

M. ÉTIENNE P. H. DUÉE J.

^LEBOST

Station de Recherches suy

l’Élevage

^{des Porcs, I. N. R. A., C. N.}

^{R. Z.,}

78350

Jouy

^en

Josas

This

study

^was made with the aim of

searching

for eventual effects of

overfeeding

^before

mating

^{on the}

reproductive performances

^of

multiparous

^sows.

^{3 6}

^adult

Large

^{White sows were}

divided into 3 groups

according

^to litter order and

weight

^at

weaning.

^One

only

^{feed was offered}

at three different levels which were

kept

^constant in each group between the

day

^after

weaning

and the

day

^of

mating.

^{The amounts allotted were} 1.5, 2.5 and 3.5

kg

per

day, respectively

ⁱⁿ

groups ^1,2 and 3.

During gestation,

^{all sows received 2}.5

kg

feed per

day.

The results did not show any difference between the three groups of animals. The

weight

variations of the sows were

comparable ; however,

^between

weaning

^and

mating

^the

weight

^loss

tended to decrease when the

feeding

^{level was enhanced}

during

^this

period.

^{911 the sows}

partu- riated,

95 p. ¹⁰⁰

having

been fertilized at the 1st oestrus. The duration of the

weaning-oestrus

interval

( 7 . 9 ,

m.4 and

8. 3 days, respectively

for groups 1, ²and

3 )

^{and the}

weaning-conception

interval

( 7 . 9 ,

13.5 and

9 .8 days)

^was short and did not differ between the groups. This ^was also the case for the number of

piglets

^born

( 9 . 9

^{on an}

average)

and born alive per litter

( 9 .6

^{on an}

average).

According

^{to this}

study,

^the

relationship

between the

reproductive performances

^{and the}

nutritional state of the sows at

mating

^{seemed to be} low. Enhancement of the

feeding

level between

weaning

^and

mating

^of

multiparous

^sows did not affect their

fertility

^{and did not lead to}

improve-

ment of their

prolificacy

^even when the latter was poor. Further

knowledge

^{of the}

physiological

mechanisms involved should lead to a more accurate determination of the consequences

of flushing.